System for producing emulsions

Abstract

A system for the continuous production of thixotropic high internal phase ratio emulsions. The system includes supply means providing individual streams of an inverter phase (an emulsifier and external phase), and an immiscible internal phase. These streams are precisely regulated as to a preselected ratio by flow rate controllers which regulate the flow responsively to pressure changes in the supply means. The internal and inverter phases are received at a selected rate and composition within a mixing means which produces the loss distribution stepwise of the internal phase progressively in amounts into the inverter phase, thereby forming a composition with the desired ratio of the internal phase, emulsifier, and external phase of the desired emulsion. A pumping means moves this composition at the selected rate to an outlet means for passing the resultant emulsion to a subsequent utilization. The pumping means also provides continuous shear sufficient to reduce the effective viscosity of the composition near to that of the inverter phase, but below the inherent shear stability point of the desired emulsion. The pumping means retains only a minor fraction of the emulsion relative to the volumetric capacity of composition movement.

What is claimed is: 
     
       1. A system for producing at a selected rate a stable, highly viscous emulsion with an internal phase content of above about 75% by volume within an immiscible external phase comprising: a. supply means providing individual stream of an inverter phase formed of an internal-in-external emulsifier and an external phase, and an internal phase;   b. first and second flow rate controller means for precisely regulating in said supply means the flow rates of separate streams of the internal phase and the inverter phase in a preselected ratio in the range of between 95 to 5, and 75 to 25 percents by volume within said system;   c. mixing means receiving the separate streams of the internal phase and the inverter phase and distributing loosely the internal phase in stepwise progressive amounts into the inverter phase, thereby forming a composition with the desired ratio of internal phase, emulsifier and external phase of the desired emulsion;   d. pumping means;   e. means for passing said composition of internal phase and inverter phase into said pumping means for moving therethrough said composition at a selected rate;   f. said pumping means providing continuous shear at rates between about 500 and 10,000 reciprocal seconds sufficient to reduce the effective viscosity of said composition near to that of the inverter phase but below the inherent shear stability point of the desired emulsion; said pumping means retaining less than 1% by volume of said emulsion relative to the volume per minute of said composition being moved;   g. outlet means for removing the resultant emulsion from said pumping means to a subsequent utilization.   
     
     
       2. The system of claim 1 wherein said mixing means distributes loosely the internal phase into the external phase in a first amount and then in successive stages the internal phase is increased stepwise in progressive amounts. 
     
     
       3. The system of claim 1 wherein said mixing means distributes loosely the internal phase into the external phase in a first amount and then in successive stages the internal phase is increased stepwise in geometric proportions relative to the external phase. 
     
     
       4. The system of claim 1 wherein said mixing means comprises an elongated vessel divided by a longitudinal plate into first and second chambers, an internal phase inlet and composition outlet in fluid communication with said first chamber at opposite ends of said vessel and an external phase inlet on said vessel near its midpoint into said second chamber, and spaced apart openings in said plate for the external phase from said second chamber to distribute loosely into the internal phase in stepwise progressive amounts. 
     
     
       5. The system of claim 4 wherein said openings in said plate increase in flow passage sizes towards said composition outlet. 
     
     
       6. The system of claim 4 wherein said openings in said plate are round holes that increase in sizes toward said composition outlet. 
     
     
       7. The system of claim 6 wherein said round holes have sizes that the internal phase is increased stepwise in geometric proportion relative to the external phase as it moves towards said composition outlet. 
     
     
       8. The system of claim 4 wherein said openings are grouped into stages in said plate and each stage has at least one opening providing distribution loosely of the external phase into the internal phase. 
     
     
       9. The system of claim 8 wherein the openings grouped in said stages have diameters increasing geometrically.